Previously, many types of separate locking devices and integral locking mechanisms have been used in endeavoring to provide an effective means for securing a trailer coupler that is attached to a motor vehicle.
The prior art listed below did not disclose any patents that possess the novelty of the instant invention, however the following U.S. patents are considered related:
U.S. Pat. No.InventorIssue Date4,776,607Richter et al.Oct. 11, 19885,205,666HollisApr. 27, 19936,000,710Schocker et al.Dec. 14, 19996,352,279EbeyMar. 5, 20026,505,849EbeyJan. 14, 20036,588,790HallJul. 8, 2003
Richter et al. in U.S. Pat. No. 4,776,607 teaches a coupler for a ball type hitch with a coupler body that includes a socket portion and a closure mechanism that moves from an open to a closed position. The closure mechanism includes a retaining plate and latch plate, with a spring for biasing. The retaining plate includes a lock receiving aperture for receiving a lock that prevents unauthorized opening of the coupler.
U.S. Pat. No. 5,205,666 issued to Hollis is for a trailer coupler having a housing with a pair of jaws that lock around a hitch ball. A jaw locking ball with a finger tab facilitates operation. A closure compression spring is located inward at one horizontally-pivoted ear extension for biasing the ball towards the jaw-locking position.
Schocker et al in U.S. Pat. No. 6,000,710 discloses a trailer coupler lock with the locking assembly mounted within a housing coupler, thus preventing withdrawal of the hitch ball from the housing. The lock includes a rotatable pin that extends transversely thorough the coupling housing to prevent withdrawal. The pin is connected to a lever that is positioned externally of the coupler housing outwardly causing a spring to bias the lever to the locked position.
Ebey in U.S. Pat. No. 6,352,279 teaches a ball clamp trailer coupler that is tightened by rotating a clamp to engage a hitch ball within the coupler socket.
U.S. Pat. No. 6,505,849 issued to Ebey is a so-called trigger lock-type trailer coupler to which the patent improvement is directed. The coupler contains a trigger latch and an actuator arm, thereby allowing the improvement to be utilized by replacing the actuator arm with an advanced arm. The advanced arm contains a keyed lock which prevents the trigger latch from rotating completely, thereby locking the coupler in place.
Hall in U.S. Pat. No. 6,588,790 discloses a remotely actuated coupler for automatically locking a trailer to a towing vehicle ball. The automatic locking mechanism is powered by a battery that is actuated by remote control. The locking mechanism also provides a manual release handle.